Smartphone gyros and open background tabs reveal your inputs, even when locked

Cyber experts at Newcastle University, UK, have revealed the ease with which malicious websites, as well as installed apps, can spy on us using just the information from the motion sensors in our mobile phones.

Analysing the movement of the device as we type in information, they have shown it is possible to crack four-digit PINs with a 70% accuracy on the first guess – 100% by the fifth guess – using just the data collected via the phone’s numerous internal sensors.
[…]
“Most smart phones, tablets, and other wearables are now equipped with a multitude of sensors, from the well-known GPS, camera and microphone to instruments such as the gyroscope, proximity, NFC, and rotation sensors and accelerometer.

“But because mobile apps and websites don’t need to ask permission to access most of them, malicious programs can covertly ‘listen in’ on your sensor data and use it to discover a wide range of sensitive information about you such as phone call timing, physical activities and even your touch actions, PINs and passwords.

“More worrying, on some browsers, we found that if you open a page on your phone or tablet which hosts one of these malicious code and then open, for example, your online banking account without closing the previous tab, then they can spy on every personal detail you enter.

“And worse still, in some cases, unless you close them down completely, they can even spy on you when your phone is locked.

“Despite the very real risks, when we asked people which sensors they were most concerned about we found a direct correlation between perceived risk and understanding. So people were far more concerned about the camera and GPS than they were about the silent sensors.”